As a positive electrode active material for lithium ion batteries, a lithium transition metal composite oxide is well known. The lithium transition metal composite oxide is produced as described, for example, in Patent document 1 in such a manner that a lithium compound and a transition metal compound are mixed to prepare a precursor for positive electrode active material for lithium ion batteries and, after that, the mixture is fired to form a composite.
A lithium ion battery is, from the uses thereof, used over a long period of time, and, because charge and discharge are repeated, various kinds of characteristics such as the cycle characteristics and storage characteristics are required, and high capacity of very high level is being demanded. Further, as a market for lithium batteries for use in consumer equipment such as portable telephones and personal computers and for use in automobiles expands, it is demanded to produce lithium ion batteries at low cost and with high efficiency.
In a step of producing lithium ion batteries like this, as described above, it is necessary to fire a precursor for positive electrode active material for lithium ion batteries to form a composite. In such a step of firing, generally, a method where a firing vessel in which the precursor is filled is set inside of a firing furnace (static furnace) and heated according to a conveyer method or a batch method is in use.    (Patent document 1) Japanese Patent No. 3334179